It seems that packets sent through using gopacket/gopcap are somehow 'sent' as they are visible in a tshark trace:
444 143.613451037 127.0.0.1 → 127.0.0.1 UDP 66 6000 → 8888 Len=22
but these packets never arrive on a process on the same machine listening on 127.0.0.1:8888 (for example netcat -ul 8888).
Does anybody have any hints on why this is or things to try? As mentioned, the packets are in fact visible in a tshark trace... they just seem to completely vanish after that.
... irrelevant
out , err := pcap.OpenLive(*iface, 65535, true, -1 * time.Second)
out.WritePacketData(buf.Bytes())
... irrevelant
The idea is to construct packets and send them on lo so that a process listening on 127.0.0.1:<some port> can actually see those packets.
IP src/dst are both 127.0.0.1 and ethernet src/dst are both 00:00:00:00:00:00.
Edit:
As far as some more research goes it seems to be the case that sending packets with pcap bypasses IP network stacks in such a way that the packets can't be seen by processes. A workaround is to strip the lower levels of the packets in the trace and open a regular udp/tcp socket and send the payload through that socket.
